Predictive value of motor-evoked potentials for upper limb functional outcomes in acute ischemic stroke

Stroke remains a leading cause of acquired physical disability globally, with upper limb motor impairment significantly affecting independence and quality of life. Currently, objective neurophysiological biomarkers are not routinely incorporated into stroke care. This study aimed to investigate the predictive value of MEPs for upper limb outcomes in acute ischemic stroke.

This prospective cohort study included 133 adults experiencing their first acute ischemic stroke. Within 10 days of onset, participants underwent Motor-evoked potential (MEP) testing via transcranial magnetic stimulation (TMS) and were categorized as MEP+ (with preserved responses) or MEP- (with absent responses). Outcome measures included the Fugl-Meyer Assessment (FMA), Barthel Index, and modified Rankin Scale (mRS), assessed at baseline and 90 days. Logistic regression models adjusted for age and baseline stroke severity were used to determine the independent predictive value of MEP status.

Among 133 patients (mean age 63.6 ± 12.2 years; 57.9% male), those with preserved MEPs (57.1%) demonstrated significantly better motor and functional outcomes at 90 days. MEP+ patients had higher FMA scores (61.0 ± 9.5 vs. 33.5 ± 25.5), Barthel Index scores (80.3 ± 25.0 vs. 57.7 ± 30.0), and greater odds of achieving minimal disability (mRS ≤ 1: 52.6% vs. 17.5%; all p < 0.001). Proportional recovery was also significantly higher in the MEP+ group for both the FMA and the Barthel Index (both p < 0.001).

Early MEP assessment is a valuable prognostic tool for upper-limb stroke recovery, supporting its routine incorporation into clinical practice.